There's a couple restaurants here in the twin cities that do it.
Here's a pic and a review from my favorite:
Blue Door Pub's Jiffy BurgerDoesn't look too appetizing, does it? Well, wait till we tell you its secret ingredient and you'll think it's even worse: peanut butter. Yep, the stuff that toddlers eat with Wonder Bread and jelly or have worked into their hair by Mom trying to loosen a glob of chewing gum. Wrinkle your nose in disgust if you must, but hear us out, because Blue Door's Jiffy Burger is tasty enough to have captured last year's City Pages Best Burger prize. The improbable combination works in the same way Asian cuisine pairs beef with peanut sauce: nutty meets meaty, plus smoky bacon and pepper jack cheese means a rich, savory indulgence like no other among the Twin Cities burger scene. It'd probably also work as a gum-in-hair remover, though we wouldn't recommend it.